We first used spectrotemporal modulations, which are a standard model of primary auditory cortex responses to sound [1]}, [2]}, [3]}, [4]}.
These features are computed by convolving spectrograms with filters that are selective to different rates of spectral and/or temporal modulation, such as changing tones or harmonics across time. We also computed spectral features (“FBANK”) by applying Mel-scale triangular filters to the power spectrum.
